BDMAN,

The piece does not really need darts - especially if one is attaching with glue on the head - but - I do have a curvy head and I stick TAPE ON THE PIECE - THE FRONT HAIRLINE OF THE PIECE - FIRST. So, the tape as I put it on the hairline of the piece "molds/freezes" the curve of the piece without my head being involved, hence the darts work a little better for me.

If you glue or put tape on your head first (I have never done the latter) and you attach a lace piece that has no tape already on it, one is able to attach while molding and stretching and tacking down the piece and as it is being applied - the piece/base curving to the contour of the head as it is being attached.

This cannot totally be the case with tape going on the piece first as that tape "freezes" the curve somewhat. If you are lucky the curve you have as you apply the tape matches you head and all is good. I find this works better for me with the darts - for the main reason is that my bald area is long and wide.

I hope that helps. I have not done any other videos. A good thing!